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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Energy Performance and Economic Evaluations of the Geothermal Heat Pump System used in the KnowledgeWorks I and II Buildings, Blacksburg, Virginia

Charoenvisal, Kongkun 14 August 2008 (has links)
Heating, Ventilating and Air Conditioning Systems (HVAC) are not only one of the most energy consuming components in buildings but also contribute to green house gas emissions. As a result often environmental design strategies are focused on the performance of these systems. New HVAC technologies such as Geothermal Heat Pump systems have relatively high performance efficiencies when compared to typical systems and therefore could be part of whole-building performance design strategies. In collaboration with the Virginia Tech Corporate Research Center, Inc., this research studies the energy consumption and cost benefits of the Geothermal Heat Pump System that has been integrated and operated in the KnowledgeWorks I and II buildings located on the Virginia Tech campus. The purpose of this thesis is to understand the energy and cost benefits of the Geothermal Heat Pumps System when compared to the conventional package variable air volume (VAV) with hot water coil heating and air-source heat pump systems using computer simulation and statistical models. The quantitative methods of building energy performance and life-cycle cost analyses are applied to evaluate the results of simulation models, the in-situ monitoring data, and the associated documents. This understanding can be expanded to the higher level of architectural systems integration. / Master of Science
12

Climate Impact from Installations of Heating Systems in Buildings : An analysis of underfloor heating and radiator systems from a CO2-perspective

Holmqvist, Anton, Magnusson, Sofia January 2024 (has links)
With the need to reduce greenhouse gas emissions in the building sector, this thesis analyzes two common heating solutions: radiator and underfloor heating. As systems with the same purpose, but with diverse installation components, it was of interest to study the climate impact of different materials. Moreover, the energy performance of the systems was investigated for two different modes of heat supply: with district heating or heat pumps. By coupling the heating systems with modes of heat supply, four models were studied. The thesis aimed at analyzing the climate impact of the models by combining the embodied and operational carbon generated during the life cycle of the heating systems, thus conducting a life cycle assessment. The operational carbon was determined by making an energy analysis in IDA ICE combined with energy carrier emission rates. With an analysis of the material and production stage of the heating systems, the embodied carbon is estimated with the software One Click LCA. The results showed that the embodied carbon had a much smaller influence on the total emissions of the building compared to the operational carbon. It was also concluded that the coupling with a heat pump was more energy efficient than having heat supplied from a district heating network. Regarding the heating systems, the underfloor heating system was slightly more efficient than the radiator heating system when coupled with the heat pump, but required more top-up heating. Throughout the study, several different aspects of the systems were encountered. Changing the district heating supplier resulted in drastic changes in the operational carbon. The electricity mix also heavily influenced the emissions produced by the heat pump. These are factors that vary greatly with the location of the project and one combination of heating and supply systems is far from obvious to be a universal solution. / Med behovet av att minska utsläppen av växthusgaser inom byggsektorn så analyserar detta examensarbete två vanliga värmelösningar: radiatorer och golvvärme. De båda systemen fyller samma syfte, men med olika installationskomponenter, vilket gör det intressant att studera klimatpåverkan av de olika materialen som systemen bygger på. Dessutom undersöktes energiprestandan hos systemen för två olika typer av värmekällor: fjärrvärme eller värmepump. Genom att kombinera värmesystemen med värmekällorna undersöktes fyra olika modeller. Examensarbetet syftade till att analysera modellernas klimatpåverkan genom att kombinera den inbyggda och operativa klimatpåverkan som genererades under värmesystemens livscykel, och följaktligen genomföra en livscykelanalys. De utsläpp som genereras från systemens driftskeden fastställdes genom att göra en energianalys i IDA ICE kombinerat med utsläpp från de olika värmekällorna. Med en analys av material- och produktionsstadiet för värmesystemen så uppskattades den inbyggda klimatpåverkan i programvaran One Click LCA. Resultaten visade att den inbyggda klimatpåverkan hade en mycket mindre effekt på byggnadens totala utsläpp jämfört med den under driftskedet. Det konstaterades också att driva värmesystemet med en värmepump var mer energieffektivt än att få det levererat från ett fjärrvärmenät. Gällande de olika värmesystemen så presterade golvvärmesystemet bättre än radiatorsystemet när det drevs med en värmepump, men det krävdes mer spetsvärme. Under studien stötte man på flera olika variationer av systemens uppbyggnad och funktion, vilket ledde till att val behövde göras för att anpassa till studiens begränsningar. Att byta fjärrvärme distributör resulterade i drastiska skillnader för driftskedets klimatpåverkan. Elmixen påverkade också kraftigt utsläppen som genererades av att driva värmepumpen. Dessa är faktorer som varierar kraftigt beroende på vart byggnaden är placerad och det gick inte att konstatera att ett värmesystem är den universiellt bästa lösningen.
13

Análise teórica e experimental do comportamento de um trocador de calor geotérmico

Martins, William Marques 23 December 2015 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-10-11T16:43:10Z No. of bitstreams: 1 William Marques Martins_.pdf: 6862880 bytes, checksum: 7ab899b6cdbfc9789b0b9a42720e96f6 (MD5) / Made available in DSpace on 2016-10-11T16:43:10Z (GMT). No. of bitstreams: 1 William Marques Martins_.pdf: 6862880 bytes, checksum: 7ab899b6cdbfc9789b0b9a42720e96f6 (MD5) Previous issue date: 2015-12-23 / FAPERGS - Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul / UNISINOS - Universidade do Vale do Rio dos Sinos / Este trabalho apresenta um estudo teórico e experimental de um trocador de calor geotérmico, tipo helicoidal água-solo, para uso como condensador em um sistema de ar condicionado. Para o experimento foi construída uma bancada composta basicamente por um reservatório térmico, uma bomba d’água, medidor de vazão, um trocador de calor com serpentina tipo helicoidal com comprimento e diâmetro de 3 e 0,27 m, respectivamente e enterrado verticalmente no solo no sentido do comprimento. Foi utilizado um sistema de aquisição de dados conectado a um computador para monitorar sete sensores de temperatura: quatro para o trocador e três para a sonda térmica de medição das temperaturas do solo em três profundidades. Os resultados obtidos com o experimento foram utilizados para obtenção da condutividade térmica do solo e, posteriormente, utilizados na comparação com o modelo teórico, elaborado no software EES. A diferença entre os resultados medidos da taxa de transferência de calor e o resultado calculado ficou em torno de 1%. O modelo também foi utilizado para analisar alguns exemplos como calcular a altura necessária do trocador de calor para atender uma determinada demanda de potência térmica para o caso de substituição do condensador de um sistema de ar condicionado. Para isso foram utilizados os dados de um aparelho de ar condicionado tipo Split, com capacidade de refrigeração de 3,52 kW (12.000 Btu/h) para analisar o comportamento do trocador com diferentes condições de projeto, chegando-se a uma profundidade calculada de 37,11 metros para atender a esta demanda. / This work presents a theoretical and experimental study of a coil-type geothermal heat exchanger, water-soil, for use as condenser in an air conditioning system. An experimental bench was constructed to analyses the heat exchanger performance. This experimental facility consists of a thermal reservoir, a water pump and flow meter, a helical heat exchanger with length and diameter of 3 m and 0.27, respectively and buried vertically at this depth. During the experiments were monitored the temperatures in seven points: four in the heat exchanger and three for measuring the soil temperatures at three different depths. The results obtained with the experiments were used to obtain the thermal conductivity of the soil. The same data were used to validated the theoretical model that was implemented in the EES platform. The difference between the measured heat transfer rate and the theoretical results was about 1%. The model was also used to determine the required length of the heat exchanger to suit a particular thermal power demand for the replacement of a condenser of an air conditioning system. For this, we used the data from a split type air conditioning unit, with a condenser thermal capacity of 3,52 kW, and to analyze the behavior of the heat exchanger with various design conditions, coming to a calculated depth 37.11 meters to meet this demand.
14

Nízkoenergetický polyfunkční dům / Low-energy multifunctional building

Maršoun, Jiří Unknown Date (has links)
The master thesis designs a low-energy mixed-use building in Dolní Kralovice. The thesis consists of three parts, architectural-construction part, environment technology of building and energy assessment report to a photovoltaic power plant. The building has two above-ground floors and a basement under part of the building. The basement includes sanitary facilities and utility room, ground floor includes a restaurant and small sports hall and first floor offices. The building is founded on reinforced concrete foundation slab and foundation pads. The vertical load-bearing structures are designed as a frame system with shear core. Horizontal load-bearing structures are designed as cast-in-place reinforced slabs. External wall is designed from aerated concrete blocks with and mineral wool insulation. The building has a flat roof. In the building is air condition and cooling system and heating is with geothermal heat pumps with a borehole collector. Part of electricity demand is covered by photovoltaics on the roof. The thesis was developed in Revit software.
15

Val av värmesystem vid nybyggnation av ett flerbostadshus i mellersta Sverige : En simuleringsstudie

Olmats, Oscar January 2023 (has links)
The choice of heating system in new residential buildings has a significant effect onthe total life cycle-cost. Rising energy prices and tougher energy demands for newbuildings creates incentive for energy- and cost-efficient solutions. The purpose ofthis project is therefore to investigate how the choice and sizing of a heating systemin a building can be performed with focus on cost-efficiency. The project is conducted as a case study on a residential building during the buildingphase on behalf of INTEC Dalarna AB, a technical engineering company. The project aim is to answer the following questions: – What heating system of district heating, ground source heat pumps or air towater heat pumps is the most cost-effective for a new residential building inthe middle of Sweden? – Is there a specific combination of a heat pump of arbitrary size and peak heating system that is particularly advantageous for the building? – Is IDA ICE suitable for simulation of energy use in buildings with heatpumps? – Does high energy-efficiency also mean high cost-efficiency for the building? The questions will be answered with building simulation software IDA Indoor Climate and Energy along with capital budgeting. The capital budgeting will be performed with net present value and payoff period for the heat pumps over choosingdistrict heating. The results of the project show that a system with ground source heat pumps with acapacity of 50 percent of the annual peak heat demand and electricity for peak loadsis the most cost-efficient option for the building. However, the most energy efficient option is a ground source heat pump with a capacity of 50 percent of the annual peak heat demand with district heating for peak loads. The project also shows that IDA ICE is suitable for simulating the performance of heat pumps in buildings.The conclusion is that a smaller system of ground source is more cost-efficient forthe building, and that the most energy efficient option is not always equal to themost cost-efficient over time.
16

Energikartläggning av förskola : Underlag för energieffektiviseringsåtgärder av byggnaden Metreven samt fördjupning avseende potential för uppfyllande av Boverkets krav gällande nära- nollenergibyggnad

Lehtonen, Joakim January 2020 (has links)
The Swedish residential sector consumes almost 39 % of Sweden’s final energy consumption. The European Union framework ”Clean Energy for all Europeans package” strives to promote a 32,5 % reduction as a result of energy efficiency measures. The Swedish legislation BBR regulates rules regarding new buildings, extensions and reconstruction of existing buildings. Excerpt 9 regards how energy is being used and determines the demands e.g. for a buildings primary energy use to be classified as a near zero energy building (NZEB). The energy use of a building, located in Västerås, Sweden, is being decided. Various energy efficiency packages are applied to a model in the simulation software IDA ICE. The results are compared with each other deciding the potential benefits of the energy efficiency measures. A substantial decrease of the energy consumption is detected, especially for the energy efficiency packages containing a geothermal heat pump (66 – 78 %). A life cycle cost analysis shows that the package containing a ventilation heat recovery system (FTX) combined with a geothermal heat pump is the optimal solution through an economical point a view. The solution yields a profit after 14 years. The analysis shows that all geothermal solutions, except a system consisting of a geothermal heat pump, FTX, energy efficient windows, rooftop insulation and a photovoltaic system, yields a profit during a 30-year investment period. None of the packages containing a district heat exchanger yield a profit. The simulation results show that by implementing any of the geothermal heat pump packages, the demands for classifying the building according to an NZE building are fulfilled. Regarding the district heating packages, only the package containing all the energy efficiency measures (energy efficient windows, rooftop insulation and PV) meets the demands to be classified as an NZE building. Regarding the environmental impact due to implementing the energy efficiency measures, the results show a reduced impact from applying the geothermal heat pump packages is equivalent to the energy consumption reductions. The results show that by implementing a district heating system, more than one additional energy efficiency measure must be applied to avoid an increased environmental impact. This thesis shows that implementing energy efficiency measures can decrease energy consumption and yield an economical profit to the existing building stock.
17

Numerical Modelling of Multiple Inclined Borehole Heat Exchangers / Numerical Modelling of Multiple Angled Borehole Heat Exchangers

Deacon, Daniel January 2023 (has links)
This research describes the development and application of a numerical modelling method for angled borehole heat exchangers in ground-source heat pump systems. Inclining the boreholes relative to the vertical axis presents an opportunity to reduce the ground level footprint of the borehole field thus allowing for the installation of geothermal systems in retrofit applications or under buildings with small footprints. The commercial code COMSOL was used to develop the computational model. A series of validation and verification studies were performed to ensure the accuracy of the modelling approach. Simulations were conducted under constant and transient heat injection, where the effect of energy load imbalance is analyzed. Additionally, the effect of discontinuous loading with natural and forced recovery cycles is investigated. When exposed to a constant heat injection rate, configurations of angled borehole heat exchangers initially perform the same as vertical borehole heat exchangers. Then, there is a relatively short period where the angled configurations have slightly decreased performance due to increased thermal interaction in the near surface. At longer times, however, there is a significant benefit in using angled borehole heat exchangers as a result of the increased ground volume in the lower portion of the field. Under transient loading conditions, the conclusions were the same as constant heat injection, although the differences were smaller when the energy loading was balanced. However, when the loading was cooling dominated, by year 10 there was a significantly better performance observed for the angled boreholes. This indicates that the configurations of angled borehole heat exchangers can withstand a higher intensity of imbalanced energy loads compared to vertical configurations. Discontinuous loading was investigated by varying the length of time heat injection would occur on a daily basis. These daily perturbations led to small performance losses in the angled boreholes due to the increased thermal interaction in the near surface. Furthermore, imposing a forced recovery on the system by circulating fluid while heat injection was off did not significantly affect the fluid temperature or ground temperature. / Thesis / Master of Applied Science (MASc)
18

Optimización teórico-experimental de sondas de calor para intercambio geotérmico (SGE) según condiciones hidrogeológicas, características geométricas y propiedades de sus materiales

Badenes Badenes, Borja 01 February 2021 (has links)
[ES] Uno de los mayores retos para el mercado de bombas de calor geotérmicas es el alto coste asociado a la perforación de los intercambiadores de calor geotérmicos. Conseguir unos intercambiadores de calor geotérmicos más eficientes reduciría dicho coste, ya que sería necesaria una menor longitud de intercambiador para obtener las mismas temperaturas de trabajo en él (misma eficiencia de la bomba de calor). La eficiencia térmica de un intercambiador de calor geotérmico está caracterizada por su resistencia térmica. Dicha resistencia térmica depende de una serie de elementos entre los que se encuentran: propiedades y caudal del fluido que recorre el intercambiador de calor, diámetro de la perforación geotérmica, geometría y materiales de la tubería del intercambiador de calor y las propiedades del material de relleno de la perforación (grouting). Cuanto mayor sea la resistencia térmica del intercambiador de calor, menor será el calor transferido entre el fluido caloportador y el terreno, traduciéndose en una necesidad mayor de longitud de intercambiador enterrado. Por lo tanto, es necesario una reducción de este parámetro al mínimo posible. En consecuencia, el objetivo principal de esta tesis doctoral consiste en, a partir de un modelo analítico comprensivo de cuantificación del impacto de los parámetros anteriores, realizar un estudio detallado para analizar su influencia combinada en la resistencia térmica del intercambiador geotérmico, pero también examinando dicho efecto en otros planos, como costes económicos de ejecución del intercambiador y de explotación (consumo eléctrico de la bomba de calor y costes de bombeo asociados). / [CA] Un dels majors reptes per al mercat de bombes de calor geotèrmiques és l'alt cost associat a la perforació dels bescanviadors de calor geotèrmics. Aconseguir uns bescanviadors de calor geotèrmics més eficients reduiria aquest cost, ja que seria necessària una menor longitud de bescanviador per a obtenir les mateixes temperatures de treball en ell (mateixa eficiència de la bomba de calor). L'eficiència tèrmica d'un bescanviador de calor geotèrmic està caracteritzada per la seva resistència tèrmica. Aquesta resistència tèrmica depèn d'una sèrie d'elements entre els quals es troben: propietats i cabal del fluid que recorre el bescanviador de calor, diàmetre de la perforació geotèrmica, geometria i materials de la canonada del bescanviador de calor i les propietats del material de farciment de la perforació (grouting). Com més gran sigui la resistència tèrmica del bescanviador de calor, menor serà la calor transferida entre el fluid termòfor i el terreny, traduint-se en una necessitat major de longitud de bescanviador enterrat. Per tant, és necessari una reducció d'aquest paràmetre al mínim possible. En conseqüència, l'objectiu principal d'aquesta Tesi Doctoral consisteix en, a partir d'un model analític comprensiu de quantificació de l'impacte dels paràmetres anteriors, realitzar un estudi detallat per a analitzar la seva influència combinada en la resistència tèrmica del bescanviador geotèrmic, però també examinant aquest efecte en altres plans, com a costos econòmics d'execució del bescanviador i d'explotació (consum elèctric de la bomba de calor i costos de bombament). / [EN] One of the biggest challenges for the ground source heat pump market is the high cost associated with drilling geothermal borehole heat exchangers. Achieving more efficient geothermal heat exchangers would reduce this cost, since a shorter exchanger length would be required to obtain the same working temperatures in it (same efficiency of the heat pump). The thermal efficiency of a geothermal heat exchanger is characterized by its borehole thermal resistance. This borehole thermal resistance depends on a number of parameters, mainly: properties and flow rate of the working fluid that flows through the borehole heat exchanger, diameter of the geothermal borehole, geometry and materials of the heat exchanger pipe and the properties of the borehole grouting material. The higher thermal resistance of the heat exchanger, the less heat is transferred between the heat carrier fluid and the ground, resulting in an increased requirement for the length of the buried heat exchanger. Consequently, it is essential to reduce this parameter to the minimum possible. Therefore, the main objective of this Ph. Doctoral Thesis is to carry out, based on a comprehensive analytical model of quantification of the impact of the above mentioned parameters, a detailed study to analyze their combined influence on the thermal resistance of the geothermal borehole, but also exploring this effect in other less researched areas, such as economic costs of running the exchanger and operating it (electricity consumption of the heat pump and associated pumping costs). / This research has received funding from the European Union’s Horizon 2020 Research and Innovation program under grant agreement No [657982], [727583] and [792355]. / Badenes Badenes, B. (2020). Optimización teórico-experimental de sondas de calor para intercambio geotérmico (SGE) según condiciones hidrogeológicas, características geométricas y propiedades de sus materiales [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160477 / TESIS
19

A Study of Energy Saving Actions in Older Buildings in Sweden / En Studie om Energibesparing i Äldre Byggnader i Sverige

LEFFLER, OSCAR, MANSOUR, NASSIF January 2018 (has links)
Modern energy saving technologies are become increasingly mature, easier to implement and financially profitable. Both the European Union and the Swedish government have directives with goals regarding energy savings for the year 2020 and 2030. Here, making buildings more energy efficient plays a large role as around 40% of the total energy usage in Europe can be related to buildings. Constructing new, nearly zero energy houses is currently very popular, but as a vast majority of all buildings in a country like Sweden are older buildings, built before 1980, a majority of the used energy will come from these buildings. Hence, there is plenty of incentive for carrying out energy saving actions and investments in older buildings. From previous research and interviews with energy consultants, it can be concluded that energy saving actions are not being carried to the extent that is possible. This thesis aims to find out why this is and mainly what the main obstacles are when implementing energy saving solutions in older buildings. A case study, consisting of eight interviews with energy consultants and real estate owners was carried out in order to get an understanding of the current situation and the different stakeholders views on this issue. The results showed that, at least in the represented cases, there is a will among real estate owners for moving forward with energy saving. An understanding has also recently emerged where most real estate owners realize that there are great financial incentives connected to implementing energy saving solutions to current, older buildings. However, increased will of making a change has not yet resulted in a majority of buildings having installed energy saving solutions. One factor for this is that each building is its own individual case and therefore needs to be handled individually due to different conditions and are therefore suitable for different energy saving actions. Other factors include lack of technical and financial understanding among some real estate owners, slow decision making processes and ownership types. The research explores theories related to decision makings to provide a comprehensive overview regarding the current situation of energy saving in Sweden, as well as a contribution to the theoretical literature regarding decision making / Modern teknik inom energibesparing blir allt mer mognare, lättare att implementera och finansiellt lönsamt. Både den europeiska unionen och den svenska regeringen har direktiv med mål för energibesparing för år 2020 och 2030. Här spelar byggnader en viktig roll, då byggnader står för ca 40 % av den totala energianvändningen i Europa. Att bygga nya, nära noll energi byggnader är för närvarande väldigt populärt. Men i ett land som Sverige, där majoriteten av alla byggnader är äldre byggnader, kommer majoriteten av energianvändningen fortfarande från dessa. Därav finns det stora incitament till att genomföra energieffektiviserande åtgärder på äldre byggnader i Sverige. Från tidigare studier och intervjuer med energikonsulter kan det fastslås att energibesparande åtgärder ej genomförs i den grad som det är möjligt. Målet med denna rapport är att utröna varför det är så samt vilka huvudsakliga hinder som kan relateras till energibesparing i äldre byggnader. För att få en överblick av den befintliga situationen samt hur olika intressenter ser på denna fråga genomfördes en fallstudie bestående av åtta intervjuer med energikonsulter och fastighetsägare. Resultaten från studien pekade på att det finns en vilja bland fastighetsägare att gå vidare med energibesparande åtgärder. På senare tid har även en förståelse vuxit fram bland fastighetsägare där man inser att det även finns stora finansiella incitament med att implementera energibesparande åtgärder på äldre byggnader. Detta har dock ännu ej lett till att energibesparande åtgärder genomförts på en majoritet av befintliga byggnader. En anledning till detta är att varje byggnad måste hanteras individuellt då alla har olika förutsättningar och därmed lämpar sig för olika energibesparande lösningar. Andra faktorer inkluderar teknisk och ekonomisk kunskapsbrist bland vissa fastighetsägare, långsamma beslutsprocesser och ägarstrukturer. Studien nyttjar teorier relaterade till beslutsfattning för att ge läsaren en överblick av den befintliga situationen kring energibesparing i Sverige. I tillägg bidrar studien till den teoretiska litteraturen om beslutsfattning.
20

LCC VÄRMESYSTEM X- En livscykelkostnadsstudie av fyra värmesystem utifrån småhus med varierande storlek, energibehov och geografisk placering.

Eriksson, Martin, Ngea Chit, Pyo January 2024 (has links)
För småhusägare finns ekonomiska incitament till att sänka det årliga energibehovet för värme och tappvarmvattenberedning, då det utgör huvudparten av det totala årliga energibehovet för bostäder i Sverige. Valet av värmesystem är därför ett viktigt då det kan medföra mer eller mindre gynnsamma ekonomiska konsekvenser sett över längre tidsperioder,då den mängd köpt energi som systemet kräver kan medföra besparingar som viktas mot den ekonomiska investeringen av systemet.Syftet med denna studie har därför varit att skapa ett referensunderlag över fyra olika värmesystem med jämförelser mot småhus av olika storlek, geografisk placering samt olikaisoleringsstandard, där det eller de mest ekonomiskt gynnsamma värmesystemen, sett över en 50-årsperiod, kan utläsas utifrån dessa parametrar.De småhus som studien har jämfört har bestått av enplanshus med tre antagna areor, 89,7/120/150,3 m2. Dessa har jämförts för Malmö, Stockholm, Sundsvall samt Luleå, varpå varje area har innefattat tre olika antagna genomsnittliga värmegenomgångskoefficienter, Umedelvärden. Studien har genomförts med energiberäkningar enligt gradtimmemetoden, och den ekonomiska analysen genom beräknade livscykelkostnader, LCC, för de olika systemkonstellationerna. Fyra värmesystem har undersökts: Fjärrvärme, bergvärmepump, luft-vattenvärmepump samt frånluftsvärmepump. Frånluftsvärmepumpen har inkorporerats som ett FX-ventilationssystem, frånluftsventilation med värmeåtervinning. De övriga tre systemen har för studien kombinerats med ett FTX-ventilationssystem, från- och tilluftsventilation med värmeåtervinning.Resultaten har påvisat att FTX-system, i jämförelse med FX-system, sänker för samtliga studerade byggnader i Malmö det årliga värmeenergibehovet, den energi som måste tillsättas byggnaden, med 36–71%, medan det i Luleå sänks med 32–61%. Den årliga energianskaffningen, den energi som måste köpas för att värmesystemen skall generera erfordrad värmeenergi och tappvarmvattenberedning, är genomgående lägst för systemkonstellationen bergvärmepump i kombination med FTX. Den systemkonstellationenmed studiens genomgående högsta andel köpt energi, är fjärrvärme i kombination med FTX.Vid jämförelse av livscykelkostnader, LCC, har påvisats att fjärrvärme i kombination med FTX är mest ekonomiskt gynnsam endast då det årliga behovet av köpt energi är mycket litet, och att det vid högre behov istället blir det dyraste alternativet. Frånluftsvärmepump utgör ett ekonomiskt gynnsamt alternativ vid majoriteten av analyserade fall, tack vare lägre investeringskostnader som väger upp de högre värmeenergibehov som ventilationstypen medför. Bergvärme i kombination med FTX, utgör det dyraste alternativet i de flesta fall därdet årliga behovet av köpt energi är lågt, men påvisar ekonomisk gynnsamhet vid höga energibehov. Luft-vattenvärmepump i kombination med FTX, är relativt likvärdig bergvärmepump men har ej påvisats vara det billigaste alternativet i något studerat fall. Vid jämförelse mellan frånluftsvärmepump och bergvärmepump i kombination med FTX, har påvisats att för studiens samtliga analyserade objekt är den största prisskillnaden, utslaget på 50 år, mindre än 1.800 kr/år.Utifrån de parametrar som presenterats, har påvisats genomförbarhet i att skapa ett referensunderlag över optimal gynnsamhet för värme- och ventilationssystem hos småhus, vilket avläses utifrån husets storlek, U-medelvärde samt geografiska placering. / For homeowners, there are economic incentives to reduce the annual energy demand for heating and domestic hot water preparation, as these constitute the main part of the total annual energy demand for houses in Sweden. The choice of heating system is therefore important as it can have more or less favorable economic consequences over longer periods of time, as the amount of purchased energy required by the system can lead to savings that weigh against the economic investment in the system. The purpose of this study has therefore been to create a reference framework for four different heating systems, comparing them across houses of different sizes, geographical locations, and insulation standards, to identify the most economically beneficial heating systems over a 50-year period, that can be interpreted based on these parameters. The houses compared in the study were single-story houses with three assumed sizes: 89.7/120/150.3 m². They have been compared in Malmö, Stockholm, Sundsvall and Luleå, with each size having three different assumed average thermal transmittance values, average U-values. The study was conducted using energy calculations based on the degree-hour method, and the economic analysis was performed using calculated life cycle costs, LCC, for the different system configurations. Four heating systems were investigated: district heating, geothermal heat pump, air-to-water heat pump, and exhaust air heat pump. The exhaust air heat pump was incorporated as an MEVHR ventilation system, mechanical exhaust air ventilation with heat recovery, while the other three systems were combined with an HRVventilation system, mechanical exhaust and supply air ventilation with heat recovery. The results have shown that HRV systems, compared to MEVHR systems, reduce the annual heating energy demand, the amount of energy that must be supplied to the building, for all studied buildings in Malmö by 36-71%, while in Luleå it is reduced by 32-61%. The annual energy procurement, the amount of energy that must be purchased for the heating systems to generate the required heating energy and domestic hot water preparation, is consistently lowest for the geothermal heat pump system combined with the HRV. The system configuration with the highest proportion of purchased energy throughout the study is district heating combined with HRV. When comparing life cycle costs, LCC, it was found that district heating combined with HRVis the most economically beneficial system only when the annual demand for purchased energy is very low, and becomes the most expensive option at higher demands. The exhaust air heat pump is a cost-effective option in the majority of analyzed cases, thanks to lower investment costs that offset the higher heating energy demand induced by this type of ventilation. Geothermal heat pump combined with the HRV is the most expensive option in most cases when the annual demand for purchased energy is low but shows economic advantages at high energy demands. The air-to-water heat pump combined with the HRV is relatively similar to the geothermal heat pump but has not been shown to be the cheapest option in any of the studied cases. When comparing the exhaust air heat pump with the geothermal heat pump combined with the HRV, it is found that for all objects analyzed in the study, the largest price difference is, averaged over 50 years, less than 1,800 SEK/year. Based on the presented parameters, the feasibility of creating a reference framework for the cost-effectiveness of heating and ventilation systems in houses has been demonstrated, which can be assessed based on the house size, U-value, and geographical location.

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